Method of feeding molten glass to molds.



y L. w. PROBGERf METHOD or PBEDING MOLTEN GLASS To Moms.

' PPPPP 0A' TTTTT II-JBD AUG. 30, l`909. I 1 ,059,634, Patented Apr. 22,1913. z H SSSSSSSSSS 2.

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UNITED sTATEs TDATENT crimen. y

LUIS vv. PRonGER, or PITTSBURGH, PENNSYLVANIA.

MnTHonpF rEnnING MoLrEN GLASS 'ro MoLns.

Specification of Letters Patent. y

Application led August 30, 1909. s erialNo. 515,271.

j molds .which move into position one at a time-to receive their proporproportiop of glass to form the desired article, yet its application hasa wider 'scope than the mere feeding to molds, as fully hereinafter setforth. Heretofore, it has been customary to employ some mechanicaldevice,` such as a knife, to' cutwoff'the supply of molten glass when amold has been filled and one i's being moved up in positionfto be lled.Another expedient has been .to interpose a vessel of some kind tocatchthe glass dliring the time required -to bring another mold intoposition, and the glass is discharged from l vacuum.

this intermediateves'sel into the mold.' Or still another expedientvhxi's bee'nfresorted to in the shape of a stopperjwhich is moved intoposition to stop up theI orifice each time a mold has been filled andwhile the next mold is coming into'position (o'be filled. -The object ofmy invention is to provide a method or process of feeding'- the moltenglass yto molds in which the stream ,'o'f molten glass v is uninteriuted in the'sense of being broken or cut o by some mechanical dev1ce.

The further object of to provide for the maintaining of the flow inglassl at such a hightemperature' as wi l insure its being in the propercondition for flowing freely, while vat the sametiine the temperaturemay be readily varied to suit different con itions. i"

To these ends my invention comprises,

i generally stated, the process of feeding molten glass to molds,consisting in conducting the freely flowing glass from the furnace'F gor melting receptacle and cuttingoff the fiow of glass to the mold bymeans of a My invention 'further comprises the heat-` ing of the streamof glass by means of eleclmy invention' is,

, ature.

- tricity, all as hereinafter s et forth and claimed.

In the accompanying drawings, Figure 1 is a front elevation partly insection of apparatus for carrying out my improved process; Fig. 2 Vis asection on the line' (2---2)` Fig. 1; and Fig. 3 is a lmodified form ofapparatus. p 4

The apparat-us for carrying out my invention may be varied from 'thatillustrated, which is a Simple form in which the numeral 2 designates aportion of a suitable glass melbting furnace or pot with the outlet 3which 1s arranged below the level of the the discharge opening 3. Thespout 4 com# municates with the chamber 5, the walls" 6 of whichare also-formed of suitable 're-4 fractory material.' The walls of the spout.

and chamber may beinelosed, for purposes, within plates 7.. At oppositesides of the Patented Apr. ae, i913.

`molten glass within the furnace, said apspout and the chamber 6 are themetal blocks or electrodes 8 and 8a formed of iron or other suitableconducting material. These electrodes are' connected up to the. wires 9and 10. The wire 9 is connected up with the suitable switch 10e.l Thewires 11 leading 'tothe switch from a suitable transformer are of'different voltages, indicated, and the wires 12 connect up with thewires I11, said wires 12 being connected with the contacts. 13 Vof, theswitch. The lever 14 is trode 8, through the molten glass as aconductor, and return -to ground by the wire -10. The resistance of themolten lass to the flow of the current from one electrode to the othercreates the proper heat to maintain the glass at the desired temper- Ifit isfound thatl 100 volts is not necessary to maintain the glass` inproper condition, lever 14 of the switch may be thrownl onto the neXtcontact when only 50` volts will pass to the electrode 8a. The outerends of the electrodes 8 and 8a, which are within the chamber 5, willact in the same manner as in the spout to keep the glass in the propercondition for running, so that the glass will freely flow from theori'ce 16 to be discharged into the molds 17, which may be mounted upona chain carrier 18 moving intermittently, so as to bring the molds insuccession under the orifice 16 t0- receive the proper amount of glassVto form the article desired. The molds after being@ lilled in thismanner, pass on to position beneath a suitable press (not shown) wherethe article is pressed.

The pipe 2O is connected up to the upper .end of the chamber 5, and saidpipe is co-nnected upto the cylinder 21 supported .in any suitablemanner. `Within they cylinder 21 is the piston 22 which is connected upto the piston-rod 23. This'piston-*rod 23 passes out through a suitableguide box and is connected to the lever .24; r1`he upper end of thelever 24 is connected to the bracket-arm 25 and the lower end otsaidlever is connected to the strap or rod 26 which may be connected up to asuitable mechanism for operating lever 24 intermittently, or the4operation may be done by hand it desired.

When the operatio-n of discharging the glass from the furnace isdiscontinued :tor any reason, it is desirable to maintain the glasswithin the spout 4 and chamber 5 in such condition that it will'not Howand yet -not be cold enough to form a hard, solid mass, and for vthispurpose 1' employ the following contro-lling mechanism: Thethermo-couple 30 passes through the wallsl of the chamber 5 and is incontact with the glass within the said chamber. The heat from the glassgenerates the electricity in the thermo-couple and this is conductedthrough wires 31 to the solenoid 32.l This solenoid 32 is constructedtooperate at a fixed temperature, and when the heat of the i glass risesabove that point, the solenoid will be operated by the current generatedby the thermo-pile. The switch 33 is connectedj tojthe .solenoid andsaid switch is adapted to unite the contacts 34 and 35.

4Wires 36 and 37 lead from the contacts -34 and 35 to thel solenoid 38.Connected'v up to the solenoid 38 is the arm 39.l The arm 39 is mountedon shaft 40 on which is car-` ried the toothed wheel 41. The weightedpawl 42 on the arm 39 engages the teeth oni wheel 41. On the wheelI 41is the arm which is yadapted to engage the cont-acts f'44 of therheostat 45. At wire' 46 connects the contact of the rheostat to theswitch 1()a and the wire 47 connects the contact of the rheo.

:stat with the wire 11 of .20` Volts.

Under ordinary conditions, let usassume the glass in such condition inthe spout that p it will not iiow. 1f the temperature of the glass risesabove the point where it will not flow, the current is reducedautomatically through ythe resistance coils 48, which are placed incircuit by the arm 43 operated through the solenoids 32 and 38, wherebythe glass is maintained at the proper'temperature so vas not to fiow. f

As soon as the electricity generated by the thermoepile operatessolenoid 32 to close the switch 33, the solenoid 38 will operate the arm39 so as to throw'the arm `43 into con# tact with one of the contacts44, the resistance coils 48 acting to increase the resistance. lAs theonly current passing through t-he electrodes=8 and 8a is carried fromthe 20-volt wire, the glass is notv in 'a moltenl temperature to lmakeit flow/freely as before.

1n this way l dispense with the necessity of remelting a' solid, coldbody of glass which would require a much greater heat and a longer time.E

If, however, the glass in the spout should be cold and in the form of asolid mass of glass, the current is turned cn and the current passes byway of the molten glass, or in linev of least resistance, at theJfurnace outlet 3, which is close to the inner ends of the electrodes.The solid mass in the trough is gradually heated and reduced to a moltenstate, beginning at the inner-end and continuing until there is aflowing stream of glass leading from the furnace to the molds. Theamount of heat generated by an electric current within a conductorvaries as the resistanceand the square of the current. The glass beingof a much higher speeic resistance than the rest of the current becomeshighly heatedand is maintained at a flowing temperature.

The total amount of glass heated by a current in a given time variesdirectly as'the amount of heat evolved by the current. The heat evolvedis varied inthe following manner: In a given stream of glass, theresistance remaining the same, thecurrent pass'- ingj will vary directlyas the voltage. By reducingthe voltage, the current is reduced, the heatevolved varying as the square of the current, changing the amount ofglass heated in a given time in proportion. 1n this manner'l can arrangetherate of ilischarge atwill. By changing the amount of current 1 canmaintain the fiowingstream at any temperature and can vary the amount ofglass discharged per minute. For instance, if with a voltage of 50 thedischarge of glass equals 12 pounds per minute, then by decreasing theamount of current thedischarge ofA Glass is decreased in propor-l tion.For di 4erent articles of glassware it is, of great value to have slightdifferences in temperature of the glass. An article weighing 15` ounces'may be shaped at a lower temperature than an aticle weighing c ounces,and this variation in temperature I readily obtain by the propervariation in the quantity of current passing through theglass. I havefound that the amount of current passing is subjected to veryslight-fluctuations and so the temperature and rate of 'flow areveryconstant. 'i .A j

In carrying out my invention with the above described apparatus,the-molten glass within the furnace 2 being raised to the2 propertemperature, flows freely therefrom .through the discharge outlet 3 asfar as the inner ends ofthe electrodes, thereby form# ing a circuit forthe current. The,current,` meanwhile, has been turned on so that theheat generated by the resistance of the molten glass will act to preventthe chilling of the glass in the spout ,and chamber 5, and willmaintainit in such a state of fluidity v that it will flow freely. Themolds 17 are `Abrought in succession into position to -receive the glgssflowing 'from the orificei 16. When suicient glass has been dischargedinto a mold, said lmold is moved away 'and another mold is brought intoposition to be charged. Pending the movement ofthe empty mold intoposition to be filled, the`y stream of@ glass flowing'from the orifice16 is interrupted for a sufficient length of time to permit the'einptymold to be brought into position and this interruption of the stream ofglass is obtained by means of a vacuum/. To create the vacuum, thepiston 22 in the lcylinder 21 is moved outwardly and a' vacuum orpartial vacuum, isrcreated' in the chamber 5 Ywhich will draw or' suckup the `molten glass "within the chamber and for thetime reqhired tobring a new mold into position will cut off the supply of molten glasslflowing through"`the orifice 16. '-By having the discharge outlet 3 ofthe furnace below the level of the glass`in said furnace, it is possibleto create the; vacuum in the above manner and the operation of the pisiton 22 is timed so as to fit in with the movement of themoldca'rier, sothat the flowvr -is interrupted in the above manner set forth,

.ends ofJsaid rods havet the inwardly projecting ends 52 at oppositesides of the orifice 16. The secondary wires 54 are connected up to therods 50, the transformers '55 being employed. The primary circuit 'isenergized intermittently to correspond with the stopping of the flow ofglass by the vacuum. A disruptive spark occurs between the ends 52 andacts to sever or remove any drippings or threads of glass eX-A tendingbelow the orifice 16, when the flow of glass is arrested as aboveset-forth.

'By my process I employ no mechanical cont-rivance between the dischargeorifice and the mold to cut off the supply of glass, but there ,is astream of glass which is in. terrupted or supported intermittently bythe action of the vacuum in such a 'manner asv to feed the moldssuccessivelyy as they are .brought up into position. f

In Fig. 3 I have shown a slightly differ-V ent form of apparatus inwhich the electrodes 15 a-re located at .the discharge opening or spout76 of the receptacle 77. Inl

thisI manner the stream fof glass flowing through the spout 76isffmaintained at the proper temperature. Thefstream of glass in thiscase is a short one only extending' through the spout 76, and not ip along stream as shown in Fig. 2. HTheheating action, however, may becontrolled in the same manner, and the stream of glass flowing throughthe spout 76 yis maintained at a proper state of fluidityaby@ theelectrodes 75. l

Wha-tI claimisa 1.' The process of feeding 'molten glass'vto yQ molds,consisting in conducting the glass from the furnace or other receptaclein a flowing stream and cutting off the stream by\' means of a vacuum.

cmolds,l consisting in conducting the glass frc-m'the 'furnace or otherreceptacle 'and intermittently/cutting offthe flowing stream solely bymeans of a vacuum.

3. The process of feeding molten'glassto molds, consistingv in*conducting the glass fiowing stream to,a bottom port and cutting off'the flow of glass throughisaid port by means of avacuum. r

fl. The process of feeding moltenf glass to molds, consisting inconducting the glass 2. The processef feedingmolten glassjto from thefurnaceior other receptacle in aA from the furnace or other receptaclein a` i flowing stream lthrough a bottom port, carrying themolds undersaid port andintermittently cuttingoff the flow of molten glass throughsaid vport by means of a vacuum.

J' 5.' The process of feeding molten glass to,

molds, consisting in carrying the'glass from the melting chamber througha passage into molds, consisting in conducting the glass a separatechamber having a bottom port from a furnace or other receptacle 1n aand/cutting olf the flow of glass through stream flowing through abottom port, and 1b said '"'port solely by means of a Vacuum Acutting othe glass at or Within said port formed Within said separate chamber. bymeans of a vacuum or'medabove the 6. TheM process of feeding moltenglass to body of glass; l n y L: molds, consisting in conducting theglass In testimony Whereofg'I, the said Luis W from a furnace or otherreceptacle in a PROEGER, have hereunto set my hand. stream ioWingthrough a bottom port, and LUIS W. PROEGER. cutting 0H the glass at onWithin said port Witnesses: by 'means of a vacuum. `RoB'r. D. TOTTEN,

7. The process of feeding molten glass to WM. STEINMEYER. f-

